Hi, 1st post here. I am not sure what the specific species is, but we have 1 cichlid and a couple of cats in a 40 gallon tank. The guy developed this bump on his head, between the mouth and left eye, it started out looking like a human pimple, for lack of a better description, but it has grown and now is bigger than the size of his eye. Its got a couple of red spots on it, and it looks just awful! The fish isnt really showing any serious signs of stress, behavior wise, he eats, and is relatively active, but this thing looks god awful! Anyone have any idea what this is? I have tried doing some searches on the internet, but no disease I can find so far corresponds to what this fish has. Thanks in advance for any suggestions!

Sorry i don't have an answer, but I have a similiar issue. One of my fish has a human pimple like growth on his tail. It has not gotten, but I am also concerned. I hope you find an answer which may in turn help me.

your description is a little broad, but here's a link to something that sounded similar to it, and also a list of akin problems in fish off another site. sorry if i'm off, but it's all i could find, esp without any pics to go off of.

Q: My fish had a pimple on the skin, and now it is a large sore. Other fish are covered with large sores and dying in droves.

A: This sounds like a bacterial disorder, either Aeromonas bacteria or Pseudomonas bacteria. This disorder is common in Koi ponds.

Treatment: Use a combination of Oxytetracycline Hydrochloride + Oxolinic Acid Powder on the fish for a two week treatment. These medications can also be used in the feed (suggested). If used in the feed, add Forma-Green to the water. Bumping up the temperature to 84 degrees fahrenheit has shown to speed up this treatment